Short-circuiting device



Jan. 15 1924. 1,480,720

' G. H- GARCELON SHORT CIHCUITING nsvxca Filed'Aug. 12, 1922 WITNESSES: INVENTOR George HG'arce/an. BY

ATTORNEY uNltr n sTA-ras. P T oFFicE.

GEORGE E. Gammon, orswrssvan'n; rmmsrm'uma, assmnon ro wits'rmqrropsn ELECTRIC a manurac'rnnme coarrwr, a conroaa'rron or rmmsrnvanm.

of Swissvale', in the county of Allegheny" 5 and State of Penns lvania,-have invented a new andluseful mprovement in Short Circuiti Devices, oflwhich the'fol lowing is a spec cation...- q I 5 ation during the normal'operating period thereof.

One. of the objects of my invention is to device, of the 7 comprises rela-' provide a 'short-circuitin character described, whic tively few parts, is simple in-cpnstruetion and operation, is very compact in arran ement and may be manufacturcdat a re av tively small expense.

A further object of my'invention is to; ro-

vide a device, of the character descr ed, which embodies a plurality ofsubstantially spherical contact-members that are loosely mounted in suitable tracks or guides for movement into, and out of, short-circuiting tator cylinder, the spherical contact members being capable of rotating freely between the guides and about constantly changing axes to efl'ect an even distribution ofwear. v

A further object of myinvention is to rovide a device, of the character described, in which the several movable contact members are retained in position by means of a cage or housing that tends to resiliently maintain the contact members out of shortcircuiting engagement with the commutator segments when the machine is either stationary, or when-it. is-operating at a very low initial speed in order to efi ect a 'repulsion operation thereof.

In the accompanying drawing,

Figure 1 is a view, partially in side ele vation and partially in vertical lon' itudinal section, of a dynamo-electric mac ine embodying a short-circuiting device construct-- cd in accordance with my invention.

Fig.2 is an enlarged vertical longitudinal sectionalview of the short-circuiting device illustrated in Fig. 1.

invention relates to short-circuitingv .10 devices and it. has particular relationf-to centrifugally-operated' mechanisms for guse with "relatively small" dynamo-electric magchines to efiect a repulsion operation during.

the starting'period and'an induction oper p Y V I segmentsfi that are mounted upon,and are partially embedded in, a body portion of engagement with the segments of a commu-' snonr-crncurrmonnvmn m :Au u-e 1:, 192 2. Ber-M10. marl.

Fig. 3 is a' vertical transverse sectional viewv taken on line III'III of Fig. 2 and illustrating the movable contact retaining member or cage in elevation.- -'Referring to thedr'awing, adynaln'o-elem w tric machine, embodying a short-ci'rcuiting deviceconstructedin a'ccordarit'ge with 'my' vention, is illustrated" as comprising a stator fram'efl that is'provided with end beli ja farotor shaft'3 is journaled in-hjearin time are provided on the end bells? an carries a commutator cylinder 5.

I The commutator cylinder preferably c'o nk prises a plurality of commutatoribais, or

insulating .material "which is molded, or. otherwise 'suitably secured, upon a sleeve member 8. V

A contact-retainihgmember or cage, indicated, as a whole, at 9, is 'slidablymounted upon the shaft 3, for axial movement, and. "comprises a' huh'portion that is; 'pro',

vided with .a substantially conical wall poi- 'tion 11. The large-end diameter of the wall;

portion 11 of the retaining meinber 9is sub stantially equal to that of the commutator cylinder 5 and, to a certain extent, the wallportion shields the exposed end portions of the commutator segments 6 from. dust, oil or other foreign matter thatmightotherwise accumulate thereonif 1 The inner surface of the wall 11 is pro vided with a plurality of equally-spaced radially extending channels or grooves .12, within each of which a. spherical 'c'ontact member 13 is mounted for radial movement under the act-ion of centrifugal force, as will be hereinafter set forth.

The retaining member 9 is resiliently biased in the direction of the commutator cylinder 5 by means of a coiled spring 14, which embraces the shaft 3 between the hub portion 10 of the rotatin 'member 9 and acollar 15 that is suitably xed to the shaft, 3. When the machine is eithe'r stationary or is operating at a very low peripheral speed, the inclined wall portion 11 of the retaining member 9, by reason of the action of the spring 14, maintains the contact memhers 13 out of engagement with the extremities of the commutator'se'gments 6 and in a position contiguous to the insulating body portion 7 of the commutator cylinder.

The hub portion 10 of the retaining memher 9 extends inwardly further than the wall portion 11 and abuts a ainst the sleeve 8 of the commutator cylinder 5, when'the retaining member 9 is movedtoits innermost position under the action of the spring 14 to maintain the periphery of the wall 11 in spaced relation with respect-to the ends of e commutator segments 6. i

\ hen the accelerating machinearmatnreattainsa predetermined peripheral velocity, the centrifugal force, actm upon the members 13, will increase to sue I an extent that i a they. willbe moved radially outwardl be- (ill tween the commutator cyllnder 5 an the inclined wall 11 of the retaining member 9 to actuate the latter, in an axial direction, against the action of the spring 14. As the contact members 13 more outwardly under the action of centrifugal force, theywill move out of engagement'with the insulating portion 7 ofthe commutator cylinder Sand into engagement with the extremities of the commutator segments 6;

When' the members'13 occupy this outer- ;.1nost position, they bridgethe space between the commutator segments 6 and the rtain-' ing member 9 to establish a short-circuit therebetwecn. The. machinc will, consequently, operate. as an induction throughout the normalv operating range thereof or as lon as the centrifugal force acting on the members 13 issutficient to overcome the forcei exerted by the spring 14.

As soon, however, as the speed of the ma chine diminishes suliiciently to permit the force exerted by the spring 14 to overcome the centrifugal force acting upon the'memhers 13, the-retaining member 9 will he moved inwurdly by the spring; that is, toward the commutator cylinder. This inward movement oi the member 9 will cause the inclined wall 11 to force the. contactmcmhcrs l3, radially inward, with a cammin; action. out of.short-cir uiting engagement with the commutator segments 6 and into their initial inactive positionsin. con lact with the insulating portion 7. The machine will then function as a repulsion motor, as hereinbeforc set forth.

By means 'of the above-described construction, a very compact iuid e eient sliort ciruniting mechanism is prliviTded-that emhodics comparatively few parts; whichjmay' motor 'axes and for movement in a radial direction into and out of ahort-circuiting engagement with the segments of said commutator cylinder and said short-cimuiting member 2. A short-circuiting devioe for a dynamo electric machine comprising a shaft, a 66inmutator cylinder mounted on said shaft and hagmg a body portion of insulating material an a riedt ereby,'-an axially movable member-bf conducting material mounted on said shaft plurality of commutator segments carandembodying"an'f'inclined wall portion provided with 'a plurality of-radially ex-, tending channels and a plurality of substantially 1 spherical contact members loosely mounted f int-"said channels for" moycme'nt about constantly'chanfiin'ga'xes and adapted to engage the insulate commutator cylinder? when r said machine is operating at vrelatively1low;starting;speeds and to move voutwardly under the action of centrifugal forc; into engagement with said 3. A short-circuiting device ,for' a combodyiportion of said mutator-type dynamo-electric machine com prising a memberadapted tobe mounted for anal movement upon the shaft'of said dynamo-eleetric machine and provided with an inclined wall portion of conducting material and a hub portioiiliidapted to abut against the commutator cylinderl to' maintain said 1 wall in spaced relation with respect to the segments thereof, aplurality of radially exbendin tracks provided 'on said axially movab e member and a substantially spherical contact member looosely mounted in each of said tracks for movement about constantl chan ing' axes and adapted to be move radially outward under the actipn of centrifugal force into'enga =ement with said commutator segments to bridge the space between said segments and said axiallymov able 'member to establish a. short-circuit therebetweim. Y I

4 4. A short circuitingadevice for a commutatorgtype dynamo-electric machine comprising a cage adaptedto be mounted upon a shaft of said dynaiiioelectric machine and provided with an inclined wan ortion of conducting material and a ho portion adapted to abut-inguinal; the commutator cylinder to maintain said wall inspaced re-e lation with respect to the segments thereon;

a plurality of y M vided on the wall-portion of said cage, and

lly extendingtrackepro-i a conducting ball loosely mounted in. each 5. A short-circuiting device for a commutator-type d amo-electric machine comprising a mem r adapted to be mounted upon the shaft of said dynamo-electric machine and provided with a substantially conical wallportion having a plurality of equally spaced radially extending channels therein, and a substantially spherical contact member loosely mounted in each of said channels for movement about constantly changing axes and ada ted to be moved radially outward under t e action of centrifugal force and'into e 1 ent with said commutator segments to ridge the s ace between said segments andsaid axia y movable members to establish a shortcircuit therebetween.

6. .A short-circuiting device for a dynamo-electric machine comprising a member adapted to be mounted for axial movement upon the shaft of said dynamo-electric I machine and provided with an inclined wall portion'of conductin material and a hub portion adapted to a at against the comaxiall mutator cylinder tomaintain said well portion in spaced relation with respect to the segments thereof; a plurality of radially extendin tracks provided in said memberl a ball 0 conducting material loosely mounted in each of said tracks for movement about constantly changing axes and adapted to be moved radially outward under the action.

of centrifugal force and into engagement with said commutator segments to kind the space between said segments and said axially movable member to establish a shortcircuit therebetween, a collar fixed to said shaft, and a spring embracing said shaft subscribed my name this 8th day of August,

GEORGE H. GARCELON. 

